The present invention relates to an EC display type of electronic timepiece which is provided with an electro-optical display device comprising electrochromic (hereinafter abbreviated to EC) display elements.
As is well known in the art, an EC display cell has higher display contrast than a liquid crystal display cell, and the EC display elements themselves possess memory capabilities. Due to these advantages, it has been proposed to use such EC display elements for display devices in electronic timepieces. However, EC display elements are strongly affected by changes in the ambient temperature, and such changes can affect the display density, the speed of response, the maximum number of display write/erase operation repetitions (hereinafter referred to as the repetition lifetime), etc. In particular, if display write operations are repetitively carried out at an ambient temperature which is higher than a certain level, then the repetition lifetime referred to above will be considerably reduced. Thus, especially in the case of a wristwatch, which may be used under various environmental conditions, the disadvantages described above impose severe limitations on the use of EC display elements, and this is one reason why EC display type electronic timepieces have not been implemented on a practical basis.
It is an objective of the present invention to overcome the disadvantages of EC dispaly elements described above, and to provide an EC display type of electronic timepiece whose repetition lifetime will not be suddenly reduced if the electronic timepiece is left in a high-temperature environment.